Improvement in processes of producing fac-simile copies of writings



EUGENIO DE ZUCOATO, OF PADUA, ITALY.

IMPROVEMENT IN PROCESSES OF PRODUCING FAC-SIMILE COPIES OF WRITINGS, &c.

Specification forming part of Letters Patent No. 157,161, dated November24, 1674 application filed June 27, 1874.

To all whom it may concern Be it known that I, EUGENIO DE ZUCGATO, ofPadua, in the Kingdom of Italy, and ternporarily of Frith street, Soho,in the county of Middlesex, England, a subject of the King of Italy,have invented or discovered new and .useful Improvements in ProducingFac-Simile Copies of Writings, Drawings, and Delineations; and I, thesaid EUGENIO DE ZUCOATO, do hereby declare the nature of the saidinvention, and in what manner the same is to be performed, to beparticularly described and ascertained in and by the following statementthereofthat is to say:

My invention has reference to the-employment of chemical agency inproducing facsimile copies of writings, drawings, and delineations, inmanner hereinafter described.

In the first place it is requisite to obtain a thin sheet of paper closein texture, and which has been highly sized and well rolled, and is ofthe substanceor thickness generally known in commerce as bank post.Other kinds of paper may prove a substitute, but I recommend as beingbest adapted for the purpose of my invention the use of such paper as Ihave described.

. In the next place the sheet of paper before described should upon oneside be entirely covered or coated with an impermeable or waterproofsubstance, such as resin dissolved in spirits of wine or oil ofturpentine; and I recommend as being being best adapted for the purposesof my invention the composition known in commerce as gilders lacquer, towhich I usually add to every three parts of the same one part ofmethylated spirit for the purpose of making the lacquer to flow morefreely and evenly during the operation of coating; and in order torender thd composition softer I add Venice-turpentine in the proportionof one-sixteenth part of the whole. These proportions, however, may varyaccording to the substance or quality of the lacquer and the quality ofpaper used. .!The ingredients, when mixed, must be allowed to bethoroughly dissolved and united before being used. This varnish must belaid on the paper evenly, which can be most conveniently done by meansof a broad and soft brush; and I recommend that this operation should berepeated twice or three times, according to the consistency of thevarnish and the quality of the paper. The paper, when so coated,

must be thoroughly dry before being used. I

recommend that sheets of paper thus prepared, should be kept ready forimmediate use. I shall in future refer to the paper so prepared, whendescribing my process, as papyrographic paper. In the next place, uponthe uncoated side of a sheet of papyrographic paper prepared in theforegoing manner and being perfectly dry, the writing, drawing, ordelineation of which fac-siinile copies are intended to be producedshould be executed with an ordidary steel pen, using for ink the liquidpreparation hereafter described, and which writing must be allowed todry.

The liquid preparation I employ for executing such writing, drawing, ordelineation consists of a caustic preparatiom'such as water which hasbeen saturated with hydrate of sodium or hydrate of potassium; whichpreparation may be colored with a suitable coloring matter, such asvandyke-brown or other coloring matter capable of withstanding the action of the alkali, and which matter will not neutralize the causticproperties of the prepa ration. This preparation I shall in future, whendescribing my process, allude to as the papyrographic ink.

In the next place, in order that the papyrographic paper which has beenwritten, drawn, or delineated upon with papyrographic ink may be usedfor producing fac-simile copies, it is necessary to remove those partsof the varnish that have been acted upon or corroded by the action ofthe said ink. This removal may be made in several ways; but I recommendthe following method, namely: Upon a pad of textile fabric, such ascalico or linen that has'been saturated with clean water, the coatedside of the written papyrographic paper is to be placed, and is to befirmly and evenly pressed down, first covering it With a sheet ofblotting-paper, the writing side being uppermost. The water from the padwill within a few minutes commence to ooze through the lines of thewriting, drawing, or delineation,and the moisture appearing on theuncoated surface should be immediately removed by means of theblotting-paper before alluded to, in order to stay any lateral action ofthe papyrographic ink. This process should be continued until all thelines of the writing are perfectly clear, which is a certain indicationthat the ink has operated sufficiently. The papyrographic paper may nowbe removed from the saturated pad, and any portions of corroded varnishthat still remain may be washed away with a soft brush. I suggest thatthe position of the papyrographic paper be occasionally changed while onthe wet'pad. The effect produced by the washing before described is toremove such portions of the varnish as have been acted upon or corrodedby the action of the papyrographic ink along the lines of the writing,drawing, or delineation which have been made. It is next necessary toform apad composed of a few sheets of blotting-paper, which must be cutslightly larger than the space occupied by the writing, drawing, ordelineation that has been executed on the papyrographic paper, while itmust be smaller than the area of the said papyrographic paper, whichmust extend beyond the edges of the pad. The pad must be then evenlymoistened with a solution of persalt of iron, and I recommend as bestadapted for the purposes of my invention a solution of persulphate ofironthat is, the liquor ferri-persulphatis of the apotheeary, hereaftercalled the papyrographic-pad solution.

Having prepared the papyrographic paper and executed the writing,drawing, or delineation upon the uncoated side and washed the same, asbefore described, and having prepared the papyrographic pad, evenlymoistened with the papyrographic-pad solution, it remains to prepare thepaper upon which the fac-simile copies are desired to be produced. Forthis purpose any ordinary writing or printing paper is more or lesssuitableif previously damped with a solution prepared as next described,and which. I denominate the papyrographicprinting solution. Thispreparation is composed of a saturated solution of ferrocyanide ofpotassium or yellow prussiate of potash of commerce, in the proportionofone part of saturated solution of prussiate of potassium to elevenparts of water. It is not, however, essential that this exact proportionshould be observed; but I have in my experience found that a solution ofthis strength is very suitable for my process.

Having prepared the papyrographic pad, the papyrographic paper bearingthe writing, drawing, or delineation desired to be copied, and the paperdamped with the papyrographic printing solution, the mode of producingthe fac-simile copies of the writing, drawing, or delineation which hasbeen executed upon the papyrographic paper is as follows: Place thepapyrographic pad, moistened or damped with the papyrographic-padsolution, upon a perfectly-flat surface, such as a piece of pasteboardor wood, and flat upon the surface of the pad place the papyrographiepaper, so that the uncoated side thereof, upon which the writing,drawing, or delineation has been executed, may

be next to the pad, and the coated or varnished side up permost; andthen, if the papyrographic paper be dry, moisten it with clean water, inorder to give an absorbing power to the exposed lines of the writing,drawing, or delineation. Flat upon the surface of the papyrographicpaper put a piece of dry blotting-paper, and upon the top of the wholethus arranged plaee another piece of pasteboard, or perfectly-flat pieceof wood or metal, and press the whole together in an ordinaryletter-copyin g press, or some modification thereof. After a few secondsthe exposed lines of the drawing, writing, or delineation will be foundimpregnated with the papyrographic-pad solution. For the dryblotting-pander is then substituted a sheet of blotting-paper damped inthe papyrographic-printing solution, which, upon being pressed againstthe papyrographie paper in the manner hereinbefore described, will befound to bear in a blue color an exact facsimile or copy of the writing,drawing, or delineation made upon the papyrographic paper. Care must betaken that the pressure is evenly distributed as far as possible.

When a sheet of the paper to be printed upon, already previously dampedwith the pa1)yrographic-priuting solution, is substituted for the dampblotting-paper, upon being treated in a similar manner to that of theblottingpaper damped in the papyrographic solution before alluded to, itwill be found, on taking it off, that a fac-simile copy of the writing,drawing, or delineation made upon the papyrographic paper has beenproduced upon it in a blue color. Without disturbing the arrangement ofthe pad and papyrographie paper, a fresh sheet of the paper to beprinted upon can be placed upon the papyrographic paper in the place ofthe sheet that has been printed, and, upon submitting it to pressure inthe manner before described, it will be found that a second copy hasbeen produced, and by continuing the process a great number of copiescan be successively obtained by using other sheets of paper' damped withthe papyrographic-printing solution.

The action that ensues is as followsthat is to say: The solution ofpersulphate of iron, called the papyrographie-pad solution, with whichthe papyrographic pad is moistened, being separated by the interveningsheet of papyrographic paper, bearing the writing, drawing, ordelineation to be copied from, and the solution of prussiate of potash,called the papyrographic-printing solution, with which the paper to beprinted upon is damped, are able to come into chemical combination bymeans of the pressure exerted by the press through the exposed parts ofthe papyrographic paper along the lines of the writing, drawing, ordelineation where the papyrographic paper has been already acted upon orcorroded by the action of the papyrographic ink, as before described.The production of a blue color results from the contact of the twosolutions, so that a writing, drawing, or delineation in blue color isobtained upon the paper damped with the papyrographic-printing solutionexactly corresponding and facsimile to the writing, drawing, ordelineation already executed on the papyrographic paper.

By varying the solution used for damping the papyrographic pad uponwhich the papyrographic paper is placed, or the solution used fordamping the paper to be printed upon, or both these solutions,fac-simile copies in other colors well known to chemists may be obtainedin like manner as before described with respect to the use of thechemical solutions before mentioned.

When it is found more convenient, the process may be slightly varied indetail.

The chemical papyrographic pad and paper to be printed upon, or eitherof them, may be manufactured beforehand, and saturated with theprescribed solutions and dried, so that when required to be used theymay be both, or either of them, simply moistened with plain water ortheir respective chemical solutions.

Instead of writing, drawing, or delineating upon the papyrographicpaper, the operator can write, draw, or delineate upon a plain sheet ofblank post paper before it is coated, and when the papyrographic ink isdry the paper can be coated with varnish on one or both sides,proceeding afterward, when dry, to wash the paper so treated and printthe copies, as before described.

Having thus described my invention, and the means of carrying it intoeffect, I would have it understood that I do not limit myself EUG. DEZUOGATO. Witnesses:

CHARLES BARLOW,

23 Southampton Buildings, London. W. WHITEHORN,

23 Southampton Buildings, London.

